On 2/14/07, Grzegorz Kossakowski <grek@tuffmail.com> wrote:
> Hello,
>
> I would like to start implementing postable source and special pipeline
> components supporting them; all leading to implementation of servlet
> services general concept. Before going into implementation details I
> would like to express my main concern.
<snip/>
>
> I think we hit here little design flaw. Transformer is atomic sitemap
> component, but servlet service is pipeline fragment. We try to treat
> pipeline as transformer and this leads to problems like outlined above.
> From the user and elegance of the sitemap point of view it's justified
> to treat servlet service as exactly one transformer (or any other
> component) because it's aimed to hide any implementation details of the
> service and service really does the processing exactly the same
> (semantically) way as transformer. Even though it's technical problem,
> it *is* serious problem and I have to admit that have no idea how to fix
> it in a clever, clean way.
>
I was wondering about this the other day when someone was posting
about implementing proper HTTP 304 status code handling (was that
you?)... My first thought was that you're going to need some kind of
extra metadata passing mechanism for those cases where the consumer or
producer is coupled to another servlet; you don't have all the
information you need to make these kind of decisions in any one spot
anymore. I haven't explored the details but could you generate a
Processing Instruction (PI) that could be used to pass such
information down the pipeline?
--
Peter Hunsberger